Extended Data Figure 1. TONSL binding to histones in vivo and in vitro.
a, Histones bridge the interaction between TONSL-MMS22L and MCM2 in cell extracts as shown by co-immunoprecipitation of Flag-HA-MCM2 WT or histone binding mutant (Y81A, Y90A)7. U-2-OS cell inducible for Flag-HA-MCM2 WT or Y81A, Y90A7 were induced for 24 hours prior to immunoprecipitation with Flag antibodies (one representative experiment out of two is shown). b, Immunoprecipitation of GFP-TONSL from solubilized chromatin of HeLa cells transiently transfected with GFP-TONSL plasmid, showing that TONSL associates with nucleosomal histones H3 and H2B (one representative experiment out of two is shown). c, Domain structure of TONSL. TPR, tetratricopeptide repeats. ARD, ankyrin repeat domain. UBL, ubiquitin-like domain. LRR, leucine-rich repeats1–4. d, Pull-down of GST-ARD with recombinant histones H3–H4 tetramers. e, f, Pull-down of in vitro-translated full length TONSL with recombinant histones H3–H4 tetramers (e) or H2A–H2B dimers (f) coupled to NHS-activated sepharose beads (one representative experiment out of three (e) and two (f) is shown). ASF1a WT and histone-binding mutant (V94R)1 were included as controls. g, TONSL ARD consists of four ankyrin repeats and uses its elongated concave surface to target the H4 tail spanning residues 12 to 23.